Can't get my texture to show up in 3D view
In hopes this can help not just you but also people finding this thread in future, here's some things to check to better understand the problem:

disconnect the image texture from the shader and manually set the base color to see if it's a texture issue at all (in OP's case it isn't)
change the background color (World Properties tab ) to see if the issue is black color of the model or transparency:


As for the solutions:

in viewport shading settings try deselecting Scene World or selecting Scene Lights:



in Material Properties tab make sure Blending Mode is Opaque:



in Shader Editor make sure the Material Output is set to All: